Experiment details

Design of the BART experiment

The basic task in BART is to pump up a virtual balloon using on-screen buttons. With each pump, the balloon grows a bit and the player gains a point, which are linked to monetary rewards — the more the players pump up the balloons, the higher their payoff. The maximum size of a balloon is reached after 128 pumps. The risk is introduced through a random, uniformly distributed, point of explosion for each balloon with the average and median explosion point at 64 pumps. The optimal strategy to maximise payoff is to perform 64 pumps. Each participant repeats this 30 times.

Prior studies

BART tasks have been commonly used in psychology research to assess risk-taking behavior. A meta-analysis of 22 studies which used the BART task found that the average number of pumps (averaged across conditions) to vary between 24.60 to 44.10 (out of 128 total possible pumps), with a weighted standard deviation of 5.93. This means that based on prior studies, on average, participants in the BART task are most likely to be risk-averse.

Part 2: Submit your choice of priors

You have interacted with different specifications from two reasonable families of prior distributions for the intercept and mean difference parameters in a poisson regression. Now, you’ll need to submit the prior you’d use to analyse the data. You do not need to specify an exact value to the hundredth decimal point — please specify an approximate value that you think is suitable.

Intercept parameter

Select your choice of priors for the intercept parameter, \(\alpha\):

Mean difference parameter

Select your choice of priors for the mean difference parameter, \(\beta\):

After, you have press the submit button you will be taken to a short survey.